With its 20-20-20 targets, implemented in the Directive 2009/28/EC, EU has committed to: reduce greenhouse gas (GHG) emissions, to increase the use of Renewable Energy Sources (RES) and increase energy efficiency. On this basis, the development of the bioenergy sector in all its own production routes is foreseeable in the very next future. Latvia is undertaking and developing different measures to be implemented in the national Renewable Energy Action Plan in order to reach the set target of 40% of final energy consumption offset by the use of renewable energy resources. Nevertheless, important improvements need to be planned in the long-term perspective. This will not only focus on the main energy sectors, but target the environmental, social and economical aspects in an expanded evaluation. Within the transition to a green energy-based system, it is necessary that the development of the most suitable strategy requires clear and feasible evaluation tools adopting a global and holistic framework. Energy planning, and the related environmental impact assessment, must be interconnected in order to correctly promote and stimulate the production and use of renewable sources within the bioenergy sector. In this light, an integrated approach e of a typical energy planning modeling tool - i.e. system dynamics modeling - and cradle-to-grave impact assessment methods - i.e. Life Cycle Assessment (LCA) - may represent a suitable, comprehensive, and analytical tool. The general objective of this dissertation is the development of an integrated analytical tool for the environmental performance evaluation of different bioenergy routes within several possible “green” policy alternatives. The main work tasks addressed were to: 1. analyze the environmental performances and sustainability of different types of bioenergy routes using different types of technologies based on Life Cycle Assessment (LCA), 2. definite the integrated analytical tool, involving the: a. development of an integrated methodology linking LCA and white box modeling through the system dynamics approach, b. analysis of the implementation of different policy measures aimed to increase RES use with a System Dynamic (SD) model. The objective of the model is to represent the casual relationships between the behavior of the complex system of the Latvian district and its underlying structure heating system. The model evaluates the combination of three different policy instruments focusing on encouraging the installation of woodfuel installations in favour of those using natural gas, c. evaluation of the impact of the Emission Trading Scheme (ETS) as a mechanism to reduce the use of fossil fuels-based energy resources within the SD model; 3. validation of the proposed system dynamic model to the Latvian district heating system. The results of this research can be addressed to different target groups at different levels, in particular: the governmental level, the energy sector (investors and operators) level, the environmental level, and the scientific level. The schemes proposed within the model can be further exploited at the European scale involving other types of policy instruments and bio-energy routes not investigated at in this step of research.